Mujica, a leftist who governed from 2010-2015, made the comment on Wednesday during a press conference when asked about a dispute between Maduro and the head of the Organization of American States, Luis Almagro, who has called Maduro "a traitor." Venezuela's socialist president has in turn accused Almagro of being a CIA agent and a traitor himself.
"I have great respect for (Maduro), I do. But that does not mean I can't say he's crazy, crazy as a goat," said Mujica, whose cantankerous personality, homespun oratory and simple ways have made him wildly popular abroad.
Venezuela is facing a severe economic crisis, with the world's highest inflation and shortages. Polls indicate most Venezuelans want Maduro out of office.